In the operation of twisting spindles, especially also multi-twisting spindles, it is conventional to wind in a preparatory doubling process at least two individual yarns which are removed from supply bobbins by placing them parallel to one another and winding them onto a cross-wound bobbin. Special care must be taken in this process in regard to a uniform removal of the two individual yarns from the supply bobbins, i.e., care must be taken that the yarns will enter the doubling process with the same tension and length whereby loop formation of the individual yarns must be prevented. A loop will result when one of the two individual yarns has extra length.
In another method, the doubling process is performed on the spindle itself before the actual twisting process takes place. Two single spun yarns are supplied as supply bobbins in a two-for-one twisting spindle. In this method it is also very important to maintain the same tension and length of the two individual spun yarns and to prevent the introduction of loops into the doubling process in order to produce a twisted yarn of high quality.
In three-for-one twisting spindles, as, for example, disclosed in German patent application 35 03 864, the protective pot, respectively, the bobbin support for the supply bobbin is also rotated counter to the rotational direction of the spindle so that upon removal of the yarns from the supply bobbins a removal balloon and thus a tension and length compensation in the yarn is provided which is especially important when using two or more yarns for producing a uniform twisted yarn. Because the supply bobbins rotate very quickly with the bobbin support and the formation of a balloon of the individual yarns, the doubled yarns are stretched so that they have the same length when subjected to the twisting process. With this arrangement, the otherwise required brake within the hollow spindle axle, as is conventional in two-for-one twisting spindles, is no longer necessary because the yarns in the removal balloon coming from the supply bobbins have the desired length and desired tension.
In a pot twisting spindle disclosed in German patent 37 11 799 for twisting one or more yarns, which are supplied by supply bobbins individually or doubled, the supply bobbins inserted into the bobbin support rotate with a slight rolling movement together with the bobbin support, thus positively effecting the removal of the individual spun yarn from the respective bobbin supply and also maintaining the desired tension and length of the two individual yarns.
It is an object of the present invention to design a method of the aforementioned kind such that the supply bobbins substantially rotate together with the bobbin support so that substantially an uninterrupted introduction of the two or more individual spun yarns coming from the supply bobbins into the initial formation zone of the twisted yarn is ensured.